23.1393GPP3GPP system - fixed broadband access network interworkingRelease 17Stage 2TS
This clause is related to the case when the UE has one or more PDN connection(s) established via a Fixed Broadband access network via PMIPv6 or GTPv2 based S2b interface and the Detach Procedures is initiated by UE or ePDG, or the UE-requested PDN disconnection procedure is triggered. It is also related to the case when the UE has no PDN connection(s) established via a Fixed Broadband access network.
The UE can initiate the Detach procedure, e.g. when the UE is power off. The ePDG may initiate the Detach procedure due to administration reason or the IKEv2 tunnel releasing.
As part of the Detach procedure for multiple PDN connectivity, steps 1 to 3 of this procedure shall be repeated for each PDN connected.
This procedure terminates both the IP-CAN session and the Gateway Control Session(s) over S9a between the BPCF and the PCRF.
Figure 7.3-1: UE/ePDG-initiated detach procedure or UE-requested PDN disconnection procedure
NOTE 1: In the roaming case, the Step 2 terminates at the V-PCRF.
If dynamic policy provisioning over S9a is not deployed, the optional steps 2, 3, 5 and 6 do not occur. Instead, the Fixed Broadband Access network may employ Fixed Broadband Access local policies.
1. The description of the IKEv2 tunnel and the PMIPv6 or GTPv2 tunnel releasing procedure is same as TS 23 402 , clause 18.104.22.168 or 22.214.171.124.
The steps in 2 and 3 describe PCC signalling to remove policies for EPC routed traffic.
2. Triggered by the IKEv2 tunnel releasing in step 1, the ePDG executes Gateway Control Session termination procedure with the PCRF as specified in TS 23.203 . This step is only applicable when S2b PMIPv6 is used.
3. Triggered by the Gateway Control Session termination received from ePDG or by the IP-CAN session termination over Gx, the PCRF (for non-roaming case) and the V-PCRF (for home routed and visited access roaming case for S2b-PMIP) and the H-PCRF (for home routed and visited access roaming case for S2b-GTPv2) executes a Gateway Control and QoS Rules Provision procedure with the BPCF or, if this is the last PDN Connection for the UE, a PCRF-Initiated Gateway Control Session Termination Procedure with the BPCF would be performed as specified in TS 23.203 . This step is applicable when either S2b based PMIPv6 or GTPv2 are used.
4 Fixed Broadband Access specific resource release procedure may be executed, as defined by Fixed Broadband Access Policy Framework specifications BBF TR-134  and BBF TR-203 . This step is out of the scope of 3GPP.
The steps in 5 and 6 describe PCC signalling to remove policies for NS-WLAN offloaded traffic. Step 5 may be triggered by the notification to the BPCF that the IMSI is not authenticated any longer (e.g. re-authentication time out) and/or the UE local IP address was released using Fixed Broadband Access procedures.
5. The BPCF sends an indication of IP-CAN session termination to the PCRF as described in TS 23.203 .
6. Triggered by previous step, the PCRF (for non-roaming case) and the V-PCRF (for roaming cases) terminates the TDF session for the UE local IP address (if applicable).